This is a follow up item which related to JDK-8202117. When test the fix for JDK-8202117, intermittent failure with java.lang.NullPointerException been observed, that exposed another bug in com.sun.jndi.ldap.EventSupport, create separated bug to track here since it's a different issue

use the same test com/sun/jndi/ldap/RemoveNamingListenerTest.java with JDK-8202117 fix patch http://mail.openjdk.java.net/pipermail/core-libs-dev/2020-March/065270.html

----------System.out:(1/15)----------
Test run OK!!!
----------System.err:(28/1638)----------
Mar 16, 2020 10:14:25 AM BaseLdapServer start
INFO: Starting server at port 63,593
Mar 16, 2020 10:14:25 AM BaseLdapServer acceptConnections
INFO: Server is accepting connections at port 63,593
Mar 16, 2020 10:14:25 AM BaseLdapServer acceptConnections
INFO: Accepted new connection at Socket[addr=/127.0.0.1,port=63594,localport=63593]
Mar 16, 2020 10:14:25 AM BaseLdapServer close
INFO: Stopping server at port 63,593
Mar 16, 2020 10:14:25 AM BaseLdapServer acceptConnections
INFO: Server stopped accepting connections at port 63,593
Mar 16, 2020 10:14:25 AM BaseLdapServer handleConnection
INFO: Connection Handler exit Socket closed
STATUS:Passed.
java.lang.NullPointerException
at java.naming/com.sun.jndi.ldap.EventSupport.removeDeadNotifier(EventSupport.java:253)
at java.naming/com.sun.jndi.ldap.NamingEventNotifier.run(NamingEventNotifier.java:180)
at java.base/java.lang.Thread.run(Thread.java:832)
java.lang.NullPointerException
at java.naming/com.sun.jndi.ldap.EventSupport.removeDeadNotifier(EventSupport.java:253)
at java.naming/com.sun.jndi.ldap.NamingEventNotifier.run(NamingEventNotifier.java:180)
at java.base/java.lang.Thread.run(Thread.java:832)
java.lang.NullPointerException
at java.naming/com.sun.jndi.ldap.EventSupport.removeDeadNotifier(EventSupport.java:253)
at java.naming/com.sun.jndi.ldap.NamingEventNotifier.run(NamingEventNotifier.java:180)
at java.base/java.lang.Thread.run(Thread.java:832)
STATUS:Failed.`main' threw exception: java.lang.NullPointerException
STATUS:Failed.`main' threw exception: java.lang.NullPointerException
STATUS:Failed.`main' threw exception: java.lang.NullPointerException

...
result: Failed. Execution failed: `main' threw exception: java.lang.NullPointerException


test result: Failed. Execution failed: `main' threw exception: java.lang.NullPointerException